I'm re-exporting my meshes for uneal. I now have two sets of uv's. One is the lightmap I set up in Maya. I import the mesh back into unreal. I check off the generate lightmaps. When I open my mesh up in the ue4 mesh editor and look at uv's, no matter what index I set the lightmap to it is the same layout. It's not my custom light map. It condenses my first uv set (index of 0) no matter which index I select.